Ski boot fixation device

ABSTRACT

A ski boot fixation device comprises a lever pivotally mounted on a support about horizontal and vertical axes in relation to the plane of a ski. Boot holding means on one end of the lever can be releasably held in operative position by a pair of cooperating pieces on the lever and the support which are urged together by a spring. The lateral stress required to free the lever from operative position is made constant, i.e. independent of vertical displacement of the lever, by means compensating for the change in the pressure of the spring due to vertical displacement of the lever.

United States Patent Salomon 1 Sept. 5, 1972 [54] SK] BOOT FIXATIONDEVICE [72] Inventor: Georges P. J. Salomon, 34 avenue de Loverchy,Annecy, France [22] Filed: June 12, 1970 [21] Appl. No.: 45,783

[30] Foreign Application Priority Data [57] ABSTRACT A ski boot fixationdevice comprises a lever pivotally mounted on a support about horizontaland vertical July 14, 1969 Switzerland ..10727/69 axes in relation tothe plane of a Boot holding means on one end of the lever can bereleasably held 52 us. Cl. ..2s0/11.35 T in Operative Position y a P ofcooperating pieces 51 Int. Cl ..A63c 9/00 the ever and the support whichare urged together [58] Field of Search 280/11 35 T by a spring. Thelateral stress required to free the lever from operative position ismade constant, i.e. in- [56] References Cited dependent of verticaldisplacement of the lever, by means compensating for the change in thepressure of UNITED STATES PATENTS the spring due to verticaldisplacement of the lever. 3,326,567 6/1967 Pronzati ..280/l 1.35 T 19Claims, 30 Drawing Figures l l l 4 ////V/////f//////// v 0 I vvxm 13 a wi I @u Hilly 4- J! p, I I 8 A 6 W7 Pahnhd Sept. 5, 1.72

ELQ-l INVENTOR ATTORNEY hunted Sept. 5, 1912 Y 3589.095

.8 Shoots-Shoot 3 INVENTOR ATTORNEY MM Sept. 5, m2

8 Sheets-Sheet 3 FIGS IN VENTOR ATTORNEY Patented Sept. 5, 1912 8Sheds-Sheet 5 nu x 1 N VE NTOR 6202665 P J. SALa/H /v ATTORNEY PatentedSept. 5, 1912 3,689,095

8 Sheets-Sheet v 6 M Q FIG.22

FIG. 25

1 N VE NTOR 6502655 P (1. Slim/no I ATTORNEY Pabnhd Sept. 5,1912 I I3,589,095

' a Sheets-Shoot v f INVENTOR 66026165 PJ JAM/ha I BY ATTORNEY PatentedSept. 5, 1972 3,689,095

a Sheets-Shut a INVENTOR ATTORNEY SKI BOOT FIXATION DEVICE Thisinvention concerns ski boot fixation devices of the type comprising bootretaining means articulated in relation to a support about at least twoaxes. The boot retaining means are releasably fixable in an operativeposition by two cooperating pieces engaged one against the other by aspring, one of these pieces being rigidly attached to the boot retainingmeans and the other rigidly attached to the support. Means are providedfor adjusting the pressure between the two pieces thereby setting thelimiting resistance of the device to unlocking.

Many fixation devices of the above type are known. However, in themajority of known devices of this type, a lifting up of the skiers foot(and hence the boot) compresses the spring so that if a transversalstress occurs whilst the boot is raised, the lateral stress required tounlock the device and release the boot is increased, which can bedangerous.

In other known types of fixation device, a raised position of the bootcauses modification of the engagement of one of the cooperating pieceson the other, in such a manner that a play may result and which allowsthe boot an unwanted freedom.

It is an object of the invention to overcome the above-outlineddrawbacks and to provide a ski boot fixation device of theabove-mentioned type in which the limiting transversal stress to freethe boot is independent of vertical displacement of the boot retainingmember.

Further objects and advantages of the invention will be apparent fromthe following description of several embodiments, made by -way ofexample, and with reference to the accompanying drawings, in which:

FIG. 1 is an elevational axial cross-section of a first embodiment ofthe invention, shown mounted on a ski and operatively holding a boot onthe ski;

FIG. 2 is a partial cross-sectional view taken along line II-II of FIG.1;

FIG. 3 is an enlarged-scale view of an element of the device cut inaxial section and shown in perspective;

FIG. 4 is a view similar to FIG. 3 for a modified element;

FIGS. 5 to 7 are schematic views of the locking device of FIG. 4 inthree positions;

FIG. 8 is a view similar to FIG. 3 for a second modified element;

FIG. 9 is a view similar to FIG. I for a second embodiment of theinvention;

FIG. 10 is a partial cross-section along line X-X of FIG. 9, the devicebeing in a position corresponding to a lateral displacement of the bootwithout lifting thereof;

FIG. 11 is a schematic view showing the disposition of the cooperatinglocking surfaces of the second embodiment in a position corresponding toFIG. 10;

FIG. 12 is a partial axial cross-section, corresponding to FIG. 9, withthe device in a position corresponding to lifting of the boot;

FIGS. 13 and 14 are views similar to FIGS. 10 and 11 showing the deviceafter a lateral displacement subsequent to lifting;

FIG. 15 is a view similar to FIG. 1 for a third embodiment of a somewhatsimilar construction to the second embodiment;

FIG. 16 is a partial cross-section along line XVI- XVI of FIG. 15showing the device after lateral displacement of the boot withoutlifting;

FIG. 17 is a schematic view showing the disposition of the cooperatinglocking surfaces of the third embodiment in a position corresponding toFIG. 16;

FIG. 18 is a partial axial cross-section, corresponding to FIG. 15,showing the device after lifting of the boot followed by lateraldisplacement;

FIG. 19 is a view similar to FIG. 16, but after the above-mentionedlifting followed by lateral displace ment;

FIG. 20 is a view similar to FIG. 17 for the position corresponding toFIGS. 18 and 19;

FIG. 21 is an axial cross-section of a fourth embodiment of theinvention mounted on a ski in operative boot-toe maintaining position,but not showing a boot;

FIG. 22 is a view of a detail of the fourth embodiment;

FIG. 23 is a view corresponding to FIG. 21, but with the boot retainingmeans raised;

FIG. 24 is a partial plan view and partial cross-section along lineXXIV-XXIV of FIG. 23 after sub-.

sequent lateral displacement of the boot retaining means;

FIG. 25 is a view similar to FIG. 1 for a fifth embodiment of theinvention;

FIG. 26 is a view corresponding to FIG. 25 but afte lifting of the bootretaining means;

FIG. 27 is an axial cross-section through a sixth embodiment of theinvention mounted on a ski and in operative boot-heel maintainingposition;

FIG. 28 is a view corresponding to FIG. 27, but with the bootmaintaining means raised; and

FIGS. 29 and 30 are views similar to FIGS. 27 and 28 for a seventhembodiment of the invention.

Referring to FIGS. 1 to 3, the device for releasably holding the toe ofa boot 1 onto a ski 2 comprises a boot retaining member 3 able to gripthe sole 4 of the toe of the boot when in an operative position.Gripping member 3 is pivoted on a support 5, itself fixed to the ski 2by means not shown, about two axes in the manner of a cardan joint. Oneof these axes is formed by a horizontal axle 6 by which member 3 ispivoted to an intermediate part 7 pivotally mounted about a verticalaxle 8 fixed to support 5. Member 3 can be releasably held in itsoperative boot-locking position (illustrated in FIG. 1) by a lockingdevice comprising two cooperating pieces, namely a steel or similar ball9 and a cooperating hollow 14. Ball 9 protrudes from a housing 10 insupport 5 into which it can be retracted against the action of acompression spring 11. Spring 11 is also lodged in housing 10 which isinternally threaded to receive an adjusting member 12 which can beturned by means of its knurled head 13 to regulate the pressure ofspring 11 on ball 9. The hollow 14 is located on member 3 so as toreceive the ball 9 when member 3 is in the operative position.

When a vertical or transversal stress is exerted on the toe of boot 1,this stress tends to displace member 3 upwards or sidewards, therebyforcing ball 9 into its housing 10 against the action of spring 11 untilball 9 is clear of the hollow 14 at which moment the fixation device isreleased, and the boot freed from the ski.

a given profile 16. In this first embodiment, the

generatrix 15 remains parallel to itself during displacement and formsan angle X with the median plane P of hollow 14. Thus, by construction,angle X is constant from one end E, of the hollow 14 to the other end ESuch a hollow, formed by a series of parallel generating lines,'hasconstantly inclined planes of contact for ball 9. Therefore, up to thepoint of release, the angle X is constant whether ball 9 is centered inthe median plane through point or in other planes such as those throughpoints 0 and S.

The compression F of spring 1 l defined by the height of ball 9 beingunchanged at the moment of release, and angle X being constant byconstruction, the lateral force D required to release the device is alsoconstant and can be expressed by the relationship:

D=Fltanx It is to be noted that the surface 17 of member 3 consists of aportion of a spherical surface of radius R centered about the point ofintersection of the axes of axles 6 and 8; hence, it can be seen thatthe compression F of the spring at the point of release, and afterreleasing, has a constant value.

In other words, with such a fixation device and notwithstanding thatboot 1 has possibly been lifted by a certain amount, the limiting stressnecessary to release the device by a transversal movement will always bethe same, however much the boot 1 has been raised from ski 2 providing,of course, that the lifting is insufficient in itself to cause releaseof the device.

It is evident that the same effect can be achieved with variousdifferent shapesof hollow 14. FIG. 4 shows a first variant in which thehollow 14 is formed from a series of generating lines forming an angle Xwith the median plane P, this angle varying along the generating linesfrom the point 0 to one end E of the hollow; from point 0 to the otherend E, of the hollow, the angle can remain constant at value X,,, asshown, or can vary.

.FIGS. 5, 6 and 7 schematically show, in plan view, the engagement ofball 9 in hollow 14 in three positions along the hollow corresponding tovarying degrees of lifting of member 3, namely the positions s, t uUU.It can be seen from these figures that the force F of the spring 11increases from a value F, to F, between positions s and u The surface istherefore constructed such that for a given spring of knowncharacteristics the releasing stress D remains at a constant value:

FIG. 8 shows a second variant of the first embodiment, in which thehollow 14 is generated by a series of curved generating lines.Preferably, the angle X formed by each generating line with the medianplane P of the hollow is only constant along the line B, A E In effect,it is along this line that the angle is determined to fix the desiredreleasing stress.

The second embodiment, shown in FIG. 9, isa heel support forpositionally maintaining the heel of a boot 1 by its sole 4. The bootgripping member 3 is pivotally mounted on a support 5, fixed to a ski 2,by means of a ball 18 rigidly connected to the support 5 by a rod 19. Inthis embodiment, one of the cooperating parts for releasably fixing thedevice in operative boot-holding position is formed by a piston 20located in a housing 21 member 3 into which it can be retracted againstthe action of a spring 22. A threaded member 23 with a knurled head 24is screwable into housing 21 to enable adjustment of the force of spring22 on piston 20.

Ball 18 is provided with a flat surface 25 against which the forwardsurface 26 of the piston 25 is urged, when the device is in theoperative boot holding position, shown in FIG. 9, and these surfacesremain applied against one another as long as the member 3 is notsubjected to a stress sufficient to move it upwards or sideways. One ofthese surfaces has a bevelled edge, in the illustrated example a bevel27 on surface 26, creating a contacting edge 28 between the two surfaceswhen the member 3 is raised. As is shown in FIG. 12, upon raising of theboot heel, edge 28 of piston 20 takes support on the flat surface 25.When a lateral stress is simultaneously exerted on the already raisedmember 3, it is the length of edge 28 which determines the value of thelateral unlocking stress.

FIGS. 10 and 11 show that the leverage tending to i return member 3 toits initial operative position after lateral displacement from thisposition has a length r. On the other hand, the leverage tending toreturn member 3 to its initial operative position after both a lateraland vertical displacement has a value r' (FIGS. 13 and 14), which has avalue less than r. The reduction of the leverage from r to r compensatesfor the increase in tension of spring 22 due to lifting of the boot 1,so that the transversal stress on member 3 to release it from operativeposition remains substantially constant.

The third embodiment, illustrated in FIGS. 15 to 20, is somewhat similarto the second embodiment, illustrated in FIGS. 9 to 14. This thirdembodiment is also a heel support comprising the same principal elementsas before, such as boot-holding member 3, support 5, ball 18, piston 20,spring 22, adjusting member 23 and bevel 27. However, in the thirdembodiment, the bevel 27 instead of having a planar surface, has acurved surface thereby creating a succession of contact edges betweenthe cooperating pieces 18 and 20. The length of these successive contactedges decreases progressively the greater the boot 1 (and hence theoperative end of member 3) is lifted above the ski 2. With such aconstruction, it is thus possible to progressively compensate for theincrease in the tension of spring 22 during lifting of the boot from theski 2 by a progressive decrease in the value of the leverage from r tor. Hence, the stress required to release the fixation device by alateral displacement will be virtually constant for any position of theboot between that illustrated in FIG. 15 and the raised position atwhich the boot is upwardly freed (FIG. 18).

The fourth embodiment, illustrated in FIGS. 21 to 24, is a toe-supportcomprising a toe-stop or holding member 3 for holding a boot 1 againstthe upper face of a ski 2. Member 3 is carried at one end of a shank 29having a point 30 at its other end. A plate 31, curved at its lower end,is fixed to shank 29. This plate has a bearing surface 41 supportedagainst the inner surface 32 of a casing 33 through which the shank 29passes by an opening 34. A push-piece 35 is maintained with point 30pressed into the apex of a conical seating surface 36 by means of aspring 37. The other end of this spring is supported by a second similarpush-piece 38 mounted on the point of a regulating screw 39 screwed intoa threaded aperture 40 in casing 33 which is afiixed to a ski 2 by means(not shown) such as screws.

In this embodiment, one of the cooperating pieces is formed of shank 29and plate 31, and is capable of oscillating on either side of alongitudinal axis Y-Y and in any direction, spring 37 tending tomaintain the shank along this longitudinal axis. The rest or operativeposition of member 3 of this fixation device is determined by bearingsurface 41 which is urged against surface 32 of casing 33, surface 32constituting the other cooperating piece.

As shown in FIG 22, bearing surface 41 has curved lateral edges 42 and43 and a straight lower edge 44. Plate 31 is incurved at its lower end(see FIGS. 21 and 23) so that contact between surfaces 41 and 32 takesplace along a series of lines of contact of decreasing length as member3 is raised. The curvature of edges 42 and 43 thus determines thepivoting points of plate 31 on surface 32. The radial distance of theseedges from axis YY fixes the limiting resistance provided by the deviceagainst unlocking. Lateral edges 42 and 43 converge together as afunction of their vertical separation from axis Y-Y. Consequently, theleverage for returning member 3 to its initial position after a lateralmovement of the boot (and hence member 3) decreases from a value a to avalue b between the points m and n. This decrease of leverage as afunction of the elevation of member 3 compensates for the increase intension of the spring from a value F to a value F. It is thus possible,by construction, to obtain the following equation or similitude:

F"biF-a FIG. 24 shows the fixation device in position after the boot toehas undergone a lifting'movement followed by a lateral displacement. Byconstruction, the fixation device enables the following inequality to beobtained:

where F" is the pressure of the spring after the vertical andtransversal movements (i.e. when in the position of FIG. 24), h, is thedistance separating the line of action of the force F of the spring fromthe point of contact 7:, and h is the distance separating the line ofaction of the force F" from the point of contact m.

In the fifth embodiment, illustrated in FIGS. 25 and 26, a heel supportfor releasably holding a boot 1 on a ski 2 comprises a holding member 3for the sole 4 of a boot heel. Member 3 is pivoted about a horizontalaxle 45 carried by a piece 46 pivotally mounted about a vertical axle 47fixed to a support 48 which is fixed to the ski by means such as screws,not shown. The cooperating pieces for releasably locking member 3 inoperative position comprise a ball 49 engaging in a trough-shaped recess50 in a part 51 of member 3 such that part 51 forms a second lever arm.The ball 49 is lodged in a housing 52 at the end of a lever 53 pivotedabout a pin 54 on support 48. At a point 55 at the other end of lever 53acts a pointed push-piece 56 urged by a spring 57 supported by a tensionregulating screw 58 threadably engaging a bore 59 in support 48. Thespring 57 thus acts according to arrow F, whilst ball 49 acts on recess50 according to arrow C, when member 3 is in its operative position.

The kinematic arrangement of levers 3, 51 and 53 is chosen such that anyincreasein the tension of spring 57 due to lifting of member 3 by anupward stress on the boot heel is compensated for by an increase in atleast one leverage. As shown in FIGS. 25 and 26, in the initialposition, the force of the ball 49 in the recess 50 has a value Cexerted along a leverage arm a about pivoting axis 54. When, uponlifting up of the heel of boot 1, the member 3 pivots in clockwisedirection to the position of FIG. 26, the force C, of ball 49 in recess50 is exerted with a leverage arm b of increased value. It is thuspossible by construction and by the shape of the different levers toobtain:

where F, is the force of spring 57 in the initial position and F theforce of spring 57 in the second position. Thus, the force C can bemaintained equal to force C, and with a constant value, so that thelateral releasing effort will also be maintained constant.

Referring to FIGS. 27 and 28, the sixth embodiment of fixation devicecomprises a boot-holding member 3 pivoted about a pin 60 in a stirruppiece 61 pivoted about a horizontal axis 62 on a support 63 fixed to theupper face of a ski 2. A lever 64 is also pivoted on support 63 about ahorizontal axle 65. Lever 64 is also pivotally attached at 66 to apush-piece 67 which is urged by a spring 68 guided in a tube 69 alsopivotally mounted at 70 on support 63. A spring tension regulating screw71 is screwed into the free end of tube 70. At the free end 72 of lever64 is provided a housing 73 for a ball 74. A trough is located insidemember 3, so as to cooperate with ball 74 to releasably lock the devicein operative position. The direction of a action of spring 68 onelbow-lever 64 varies according to the load thereon due to modificationof the position of member 3 by movement of the boot heel relative to theski. The device is constructed such that the active component of theforce of spring 68 tending to prevent any lateral displacement of member3 remains substantially constant despite any supplementary constraintresulting from lifting of member 3. In other words, the arrangement issuch that:

where F, is the force of the spring in the initial (operative) position,F is the force of the spring after displacement of member 3 by boot 1, aand b are the values of the leverage of the forces F and F 2 about theaxis of axle 65, and L and L, are the values of the leverage of theforces C and C of the ball 74 on arm 3 about the axis of axle 65 in theabove-mentioned positions.

Of course, the seat of ball 74, i.e. the trough 75, can have variousshapes, its function being to ensure a constant lateral unlocking of thedevice when the effort ex-' erted on the ball 74 is itself constant.

FIGS. 29 and 30 illustrate a final embodiment of the inventioncomprising a boot-holding member 3 pivoted about a horizontal axle 76 ona hub 77. This hub is fixed on a vertical pin 78 which is rotatably heldin a support 79 is provided a housing 80 inside which are lodged twoballs 81 and 82. A spring 83, the pressure of which can be adjusted by aregulating screw 84, acts on ball 82. Spring 83 thus tends to driveballs 82 and 81 out of housing 80 through a lateral opening 85 insupport 79. Ball 81 cooperates with a trough 86 on the internal face ofa prolongation 87 of member 3 to releasably lock member 3 in theoperative position (FIG. 29).

Such a construction also enables the useful component of the force F ofspring 83 to be fixed at a substantially constant value, despite anysupplementary constraint due to displacement of member 3 from itsinitial position (FIG. 29) to another position (e.g. that of FIG. 30) asa result of vertical stresses on a boot held thereby.

The force F 1 of spring 83 on ball 82 is composed into a force F, ofball 82 on ball 81, and a force C of ball 81 acting on trough 86. It isthus possible, by construction and by suitably choosing the diameters ofballs 81 and 82, to ensure that force C remains substantially constant,i.e. that C is substantially equal to C Force C results from thecomponents of force F after raising of the boot, i.e. a component F, ofball 82 on ball 81 and a component (I, of ball 81 on trough 86.

All of the above-described and illustrated embodiments are applicableequally well to toe supports as to heel supports. Of course, in all ofthe embodiments, one or more supplementary levers, rods, pivots orballjoints could be provided either to facilitate locking of the deviceor possible to enable manual release. Certain parts of theabove-described fixation devices could be directly placed onto the skiboot sole. All the described devices ensure that the lateral unlockingeffort remains substantially constant whatever be the elevation of theboot from the ski. All of these devices can also be used to obtain anycorrection of the lateral unlocking effort, for example a degression ifjudged necessary. Of course, certain of the operating principles of thevarious embodiments could be combined into one fixation device. Thus,for example, the particular shapes of the trough illustrated in FIGS. 3,4 and 8 could be applied to the devices illustrated in FIGS. 27 to 30.

I claim:

1. Ski boot fixation device comprising a support fixable onto a skidefining a plane of reference, a member pivoted at least indirectly onthe support about at least two axes comprising an axis vertical to saidplane and an axis horizontal to said plane, means on the member forpositionally maintaining at least a part of a ski boot relative to saidski when the member is in an operative position, means for releasablyholding the member in operative position including a pair of cooperatingpieces, one of whichis on the member and the other of which is at leastindirectly on the support, a spring urging together said pieces when themember is in the operative position, means for adjusting the bearingpressure of said pieces and thereby determining the limiting stresses onthe member necessary to release the member from the operative positionby pivoting about said vertical or said horizontal axis, and means formaintaining the releasing effort constant in a horizontal directionregardless of the stress exerted upon said member in a verticaldirection.

2. A device according to claim 1, wherein one of said cooperating piecesis a hollow and the other a projection removably engageable in thehollow, the hollow being symmetrical about a median plane through saidvertical axis and defining two halves of the hollow, each half hollowhaving a shape generated by displacement of a generatrix along a givenprofile in the median plane.

3. A device according to claim 2, wherein the generatrix remains at aconstant angle to the median plane during displacement along theprofile.

4., A device according to claim 2, wherein the angle between thegeneratrix and the median plane varies according to the position of thegeneratrix along the profile.

5. A device according to claim 2, wherein the generatrix is a straightline.

6. A device according to claim 2, wherein the generatrix is a curvedline.

7. A device according to claim 2, wherein the profile is V-shaped.

8. A device according to claim 2, wherein the generatrix intersects thesurface of the piece including the hollow at a constant angle duringdisplacement along the profile.

9. A device according to claim 1, wherein the member is pivoted about aball fixed to the support, a

first planar surface on the ball forming one of the cooperating pieces,a spring-urged piston having a second planar surface forming the otherof the cooperating pieces, the planar surfaces being applied together ina resting position of the member, one of the planar surfaces having abevel forming a contact edge between said pieces upon verticaldisplacement of the member, the length of the bevel and hence thecontact edge being less than the maximum horizontal edge of contactbetween the first and second planar surfaces when applied together inthe resting position of the member.

10. A device according to claim 9, wherein the bevel is curved so as toform a contact edge the length of which progressively decreases withincreased vertical displacement of the member.

1 1. A device according to claim 1, comprising a shaft supporting-themember, a plate on the shaft having a bearing surface forming one of thecooperating pieces, a cooperating surface on the support forming theother of the cooperating pieces, and a spring acting on the shaft toapply the bearing surface on the cooperating surface and tending tomaintain the shaft along a defined axis, wherein the shaft is oscillablefrom said axis in all directions by pivoting about points determined bythe points of contact of the bearing surface on the cooperating surface,and the plate is shaped so that the horizontal separation of the lateralpoints of contact of the bearing surface on the cooperating surface fromthe line of action of the spring decreases with raising of the member.

12. A device according to claim 1, comprising means causing said piecesto bear against one another at a constant pressure for any setting ofsaid adjusting means independent of said vertical displacement of themember.

13. A device according to claim 12, wherein one of the pieces is mountedon a lever pivotally mounted on the support about a second horizontalaxis, the spring acting on the leverto urge the other piece against theone piece along a line of action, said vertical displacement of themember causing the lever to pivot to compress the spring and to increasethe lever arm of the line of action of the other piece about the secondhorizontal axis.

14. A device according to claim 12, wherein one of the pieces is mountedon a lever pivotally mounted on the support about a second horizontalaxis, the spring being pivotally mounted on the support and on the leverto urge the lever with a variable force along a variable first line ofaction depending upon the magnitude of said vertical displacement of themember, the other piece acting on the one piece along a second line ofaction such that the product of the forceof the spring and separation ofthe first line of action about the second axis divided by the separationof the second line of action from the second axis remains constantduring said vertical displacement of the member.

15. A device according to claim 12, wherein one of the pieces is a firstball urged against the other piece by a second ball, the spring urgingthe second ball along a line of action non-axial to the first ball, saidvertical displacement of the member urging the first ball towards theline of action of the spring.

16. In a ski boot (1) binding device of the kind including a basefastened to the upper face of a ski (2), a member (3) pivotallyconnected to the base (5) for pivoting at least in a plane parallel tothe upper face of the ski about a vertical axis (8) and in a planeperpendicular to the upper face of the ski about a horizontal axis (6),and means cooperating for releasably holding said member (3) inoperative position, one such means being provided on said base (5) andthe other means being provided on said member (3), the means on saidmember being a hollow (l4) and the means on said base being a projection(9) urged by means of a spring (11) into said hollow (14), and means foradjusting the bearing pressure of said spring (11), the improvementwherein said hollow (14) is shaped so that the maximum stress requiredto be exerted on said spring (1 l) to release said member (3) from itsoperative position when said member (3) is pivoted in a plane parallelto the upper face of the ski, remains unchanged in case said member (3)is simultaneously pivoted in a plane perpendicular to the upper face ofthe ski.

17. Device according to claim 16 wherein the surface of said hollow (14)is shaped in its vertical direction so that an increased stress isexerted on said spring (11) when said member (3) is pivoted verticallyupwards and wherein the length of the profile along which saidprojection (9) has to travel horizontally to apply to said spring (11)the on pressure required for releasing said member (3) when the latteris pivoted either to the right or to the left, is progressively reducedin accordance with the increased pressure exerted member (3), saidspring (11) during said simultaneous vertical displacement of saidmember (3), the angle (X) of the horizontal profile with a verticalmedian plane (P) of saidh [low 14 re ainin ch e l8. evic e ac cor mg toc dim WW erein the surface of said hollow (14) is shaped in its verticaldirection so that an increased stress is exerted on said spring (11)when said member (3) is pivoted vertically upwards and wherein the angle(X) which a vertical median plane (P) of said hollow (14), forms withthe horizontal profile along which said projection (9) has to travelhorizontally to apply to said spring (1 1) the maximum pressure requiredfor releasing said member (3) when the latter is pivoted either to theright or to the left, is progressively increased in accordance with theincreased pressure exerted on said spring (11) during such simultaneousvertical displacement of said member (3), the length of the profileitself remaining unchanged.

19. Device according to claim 16 wherein the surface of said hollow (14)has an outwardly curved profile in both vertical and horizontaldirections, the curves compensating each other so that in the outerareas, left or right, of the horizontal profile, the maximum pressure,which said projection (9) has to apply to said spring (1 l) forreleasing said member (3), remains unchanged whatever the simultaneousupwards displacement of said member (3) may be.

1. Ski boot fixation device comprising a support fixable onto a skidefining a plane of reference, a member pivoted at least indirectly onthe support about at least two axes comprising an axis vertical to saidplane and an axis horizontal to said plane, means on the member forpositionally maintaining at least a part of a ski boot relative to saidski when the member is in an operative position, means for releasablyholding the member in operative position including a pair of cooperatingpieces, one of which is on the member and the other of which is at leastindirectly on the support, a spring urging together said pieces when themember is in the operative position, means for adjusting the bearingpressure of said pieces and thereby determining the limiting stresses onthe member necessary to release the member from the operative positionby pivoting about said vertical or said horizontal axis, and means formaintaining the releasing effort constant in a horizontal directionregardless of the stress exerted upon said member in a verticaldirection.
 2. A device according to claim 1, wherein one of saidcooperating pieces is a hollow and the other a projection removablyengageable in the hollow, the hollow being symmetrical about a medianplane through said vertical axis and defining two halves of the hollow,each half hollow having a shape generated by displacement of ageneratrix along a given profile in the median plane.
 3. A deviceaccording to claim 2, wherein the generatrix remains at a constant angleto the median plane during displacement along the profile.
 4. A deviceaccording to claim 2, wherein the angle between the generatrix and themedian plane varies according to the position of the generatrix alongthe profile.
 5. A device according to claim 2, wherein the generatrix isa straight line.
 6. A device according to claim 2, wherein thegeneratrix is a curved line.
 7. A device according to claim 2, whereinthe profile is V-shaped.
 8. A device according to claim 2, wherein thegeneratrix intersects the surface of the piece including the hollow at aconstant angle during displacement along the profile.
 9. A deviceaccording to claim 1, wherein the member is pivoted about a ball fixedto the support, a first planar surface on the ball forming one of thecooperating pieces, a spring-urged piston having a second planar surfaceforming the other of the cooperating pieces, the planar surfaces beingapplied together in a resting position of the member, one of the planarsurfaces having a bevel forming a contact edge between said pieces uponvertical displacement of the member, the length of the bevel and hencethe contact edge being less than the maximum horizontal edge of contactbetween the first and second planar surfaces when applied together inthe resting position of the member.
 10. A device according to claim 9,wherein the bevel is curved so as to form a contact edge the length ofwhich progressively decreases with increased vertical displacement ofthe member.
 11. A device according to claim 1, comprising a shaftsupporting the member, a plate on the shaft having a bearing surfaceforming one of the cooperating pieces, a cooperating surface on thesupport forming the other of the cooperating pieces, and a spring actingon the shaft to apply the bearing surface on the cooperating surface andtending to maintain the shaft along a defined axis, wherein the shaft isoscillable from said axis in all directions by pivoting about pointsdetermined by the points of contact of the bearing surface on thecooperating surface, and the plate is shaped so that the horizontalseparation of the lateral points of contact of the bearing surface onthe cooperating surface from the line of action of the spring decreaseswith raising of the member.
 12. A device according to claim 1,comprising means causing said pieces to bear against one another at aconstant pressure for any setting of said adjusting means independent ofsaid vertical displacemenT of the member.
 13. A device according toclaim 12, wherein one of the pieces is mounted on a lever pivotallymounted on the support about a second horizontal axis, the spring actingon the lever to urge the other piece against the one piece along a lineof action, said vertical displacement of the member causing the lever topivot to compress the spring and to increase the lever arm of the lineof action of the other piece about the second horizontal axis.
 14. Adevice according to claim 12, wherein one of the pieces is mounted on alever pivotally mounted on the support about a second horizontal axis,the spring being pivotally mounted on the support and on the lever tourge the lever with a variable force along a variable first line ofaction depending upon the magnitude of said vertical displacement of themember, the other piece acting on the one piece along a second line ofaction such that the product of the force of the spring and separationof the first line of action about the second axis divided by theseparation of the second line of action from the second axis remainsconstant during said vertical displacement of the member.
 15. A deviceaccording to claim 12, wherein one of the pieces is a first ball urgedagainst the other piece by a second ball, the spring urging the secondball along a line of action non-axial to the first ball, said verticaldisplacement of the member urging the first ball towards the line ofaction of the spring.
 16. In a ski boot (1) binding device of the kindincluding a base (5) fastened to the upper face of a ski (2), a member(3) pivotally connected to the base (5) for pivoting at least in a planeparallel to the upper face of the ski about a vertical axis (8) and in aplane perpendicular to the upper face of the ski about a horizontal axis(6), and means cooperating for releasably holding said member (3) inoperative position, one such means being provided on said base (5) andthe other means being provided on said member (3), the means on saidmember being a hollow (14) and the means on said base being a projection(9) urged by means of a spring (11) into said hollow (14), and means foradjusting the bearing pressure of said spring (11), the improvementwherein said hollow (14) is shaped so that the maximum stress requiredto be exerted on said spring (11) to release said member (3) from itsoperative position when said member (3) is pivoted in a plane parallelto the upper face of the ski, remains unchanged in case said member (3)is simultaneously pivoted in a plane perpendicular to the upper face ofthe ski.
 17. Device according to claim 16 wherein the surface of saidhollow (14) is shaped in its vertical direction so that an increasedstress is exerted on said spring (11) when said member (3) is pivotedvertically upwards and wherein the length of the profile along whichsaid projection (9) has to travel horizontally to apply to said spring(11) the on pressure required for releasing said member (3) when thelatter is pivoted either to the right or to the left, is progressivelyreduced in accordance with the increased pressure exerted member (3),said spring (11) during said simultaneous vertical displacement of saidmember (3), the angle (X) of the horizontal profile with a verticalmedian plane (P) of said hollow (14) remaining unchanged.
 18. Deviceaccording to claim 16 wherein the surface of said hollow (14) is shapedin its vertical direction so that an increased stress is exerted on saidspring (11) when said member (3) is pivoted vertically upwards andwherein the angle (X) which a vertical median plane (P) of said hollow(14), forms with the horizontal profile along which said projection (9)has to travel horizontally to apply to said spring (11) the maximumpressure required for releasing said member (3) when the latter ispivoted either to the right or to the left, is progressively increasedin accordance with the increased pressure exerted on said spring (11)during such simultaneous vertical displacement of said member (3), thelength of the profile itself remaining unchanged.
 19. Device accordingto claim 16 wherein the surface of said hollow (14) has an outwardlycurved profile in both vertical and horizontal directions, the curvescompensating each other so that in the outer areas, left or right, ofthe horizontal profile, the maximum pressure, which said projection (9)has to apply to said spring (11) for releasing said member (3), remainsunchanged whatever the simultaneous upwards displacement of said member(3) may be.